Non-destructive Analysis of Ancient Bronze Swords Possessed at Archaeological Research Laboratory of Hiroshima University <Research and Studies at the Department of Archaeology: Article>

Eight ancient bronze swords possessed at archaeological research laboratory of Hiroshima University were investigated non-destructively. Gamma-ray radiography using 137Cs and 60Co were developed to obtain transmission images of swords. X-ray fluorescence analysis were applied for the characteristic and qualitative elemental analysis of the swords. Magnetic response were also utilized to know the distribution of iron cores. It has been identified that all bronze swords has iron cores inside of the grip part of the sword. Up to now, existence of iron cores were assumed as a ritual symbol or functional meaning, but, it has revealed that these swords had originally iron blade, which were replaced to present bronze blade just to raise the commercial value. The connecting part was soldered and painted in bronze color. These findings are deeply related to the process of the production of bimetal swords in ancient Iran. Further researches on the ancient bimetal swords are needed

Development of VGCF/MP Reinforced Al Matrix Composite by Low Pressure Infiltration Method and Their Thermal Property

To fabricate vapor grown carbon fibers and mesophase pitch reinforced Al matrix (VGCF/MP/Al) composites, porous VGCF/MP with high porosity was fabricated using the spacer method. Carbonization and electroless Ni plating were carried out on porous VGCF/MP to improve its thermal conductivity (TC) and wettability with Al matrix, respectively. In addition, VGCF/MP/Al composites were manufactured using a low pressure infiltration method at 0.1 MPa. The effect of volume fraction of VGCFs on the interface between VGCF/MP and Al matrix, and the reactivity of the Al matrix to the Ni plating were investigated. The composites with 0.5 vol% of VGCFs showed a bonded interface between VGCF/MP and Al matrix. The bonded interface can be attributed to the improved wettability between VGCF/MP and Al matrix from Ni plating, resulting in the good bonding seen between VGCF/MP and Al matrix. At the interface of this sample, an intermetallic compound, Al3Ni, formed from the reaction between Ni and Al. Furthermore, the thermal conductivities of the fabricated porous VGCF/MP and VGCF/MP/Al composites were determined

Effect of Mn or Co on Kinetics of Eutectoid Decomposition in Sintered -Fe 2 Si 5 Alloys

The evolution of the eutectoid decomposition, -Fe 2 Si 5 ! -FeSi 2 + Si, in sintered -Fe 2 Si 5 alloys with added Mn or Co has been traced by measuring the electrical resistivity under isothermal conditions. The time-temperature-transformation (TTT) diagram was obtained for each alloy, and presents a typical C shape in the temperature range of 873-1148 K. The addition of Mn or Co decreases the overall transformation rate, prolonging both the induction and transformation periods. The kinetics of the eutectoid reaction is discussed in the theoretical framework of Johnson-Mehl-Avrami (JMA) theory. It was found that the transformation mechanism of the eutectoid reaction is not affected by the addition of Mn or Co, and the effective activation energy of the Mn-or Co-added alloy is the same as that of the non-doped alloy. The added Mn or Co causes the decrease in the pre-exponential constant K 0 , which decreases the overall transformation rate